If you are a  Spanish speaker, here is one technique you can use to reduce your accent.

Words in Spanish do not typically end in a consonant clusters but English words frequently do. Since Spanish speakers are not accustomed to articulating consonant clusters (without vowels) at the end of words they frequently leave off a consonant sound.

One accent reduction technique to help with this problem is to use linking. Here is how it works:
When a word ends in a consonant sound and the next word begins with a vowel, try to use the last consonant to link those words together.

Here are a few examples:
In the phrase We worked on it link the ‘d’ (which has a /t/ sound) to the ‘o’ so that it sounds like We work don it.

In the phrase I liked it link the ‘d’ (which has a /t/ sound) to the ‘i’ so that it sounds like I like tit.

In the phrase I loved it, link the ‘d’ to the ‘i’ so that it sounds like I love dit.

In the phrase I studied economics link the ‘d’ to the ‘e’ so that it sounds like I study deconomics.

The above phrases may look a bit silly when written like this but it represents the way we SAY them.

Don’t forget that leaving the last sound off a word will contribute to your accent!

We also connect words when the first word ends with a consonant sound and the next word begins with a vowel sound.
about it sounds like aboudit
passed out sounds like passdout

If you use liaisons like native speakers do your speech will sound smoother and less choppy to American listeners.

Ann Cook’s book American Accent Training does an excellent job of teaching you to use linking to improve your accent.

Here is some more information about how to improve your American English pronunciation using linking or liaisons.
Liaisons in American English

Spoken English has linking between words and also within words.

Word internal linking occurs when there are 2 vowel sounds inside a word. When this happens native English speakers will insert a /y/ or /w/ glide  to connect the sounds.

The /y/ insertion is very common. This is sometimes referred to as the invisible /y/. Here are a few examples:

reunion sounds like reyunion
client sounds like cliyent
diet sounds like diyet

You will also hear a /w/ insertion is some words:
cooperate sounds like cowoperate
graduate sounds like graduwate
coersion sounds like cowersion

Click on the LINKING category to your right to learn more about the importance of linking in American English!

Whenever people speak, they have a tendency to save energy by connecting sounds together. This connected or reduced speech is not necessarily sloppy or informal, it’s the way most Americans speak English in everyday situations.

Reduced or connected speech may include:

• contractions
• linking sounds together
• sound assimilation
• epenthesis or addtion of certain sounds
• deletion of certain sounds

There are rules and patterns you can learn that will help you understand and use American English reduced speech forms.

For students of English who want to learn more about reduced and connected speech I suggest Nina Weinstein’s Whaddaya Say?
Whaddaya Say? Guided Practice in Relaxed Speech, Second Edition

Teachers of American English pronunciation can learn all of the technical details of assimilation, epenthesis and deletion by reading Celcia-Murcia and Brinton’s classic book, Teaching Pronunciation.
Teaching Pronunciation: A Reference for Teachers of English to Speakers of Other Languages

The other reason the word final ed can be difficult to hear is because native English speakers link words together so that the /d/ & /t/ sounds become part of the following word. That means that:

passed out sounds like pass dout

looked over sounds like look dover

talked about sounds like talk tabout

laughed at sounds like laugh tat

Click here to read more about this on my post called  How to pronounce ed in American English.

Here are 2 common types of linking in American spoken English.

Consonant to vowel linking

When words that end in a consonant sound are adjacent to words that begin with a vowel sound the consonant sound becomes part of the second word. To link these words together hold the consonant sound of the first word until you say the vowel sound of the second word. 

Here are some examples:

1.. likes it = likes-sit

2. laughed at = laught-tat

3. explain it = explain-nit

In the above phrases the consonant is the last sound of the first word and the first sound in the adjacent word.

Vowel to vowel linking

When words that end in a vowel sound are adjacent to words that begin with a vowel sound  English speakers add a /y/ or /w/ sound to link them together.

Here are some examples:

1. too + early = toowearly

2. who + is + it = whowizit

3. I + am = Iyam

If you can use linking when you are speaking with Americans your accent will improve and people will understand you more easily!

Eva Easton has some nice lessons on linking in English pronunciation on her website.

You can also read and print my article called Improve Your American English Pronunciation and Reduce Your Accent With Linking.